The invention relates to a preparation with a content of α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H)triethanol. The preparation is formulated as semi-concentrate. The invention further relates to the use of the preparation for the preservation of water-based products and processes.
The product Grotan® WS (Schilke & Mayr GmbH, Norderstedt, Federal Republic of Germany) comprises about 80% by weight of the formaldehyde depot compound α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H)triethanol (N,N′,N″-tris(2-hydroxypropyl) hexahydrotriazine, hereinbelow TTT). TTT is prepared by condensation of 1-aminopropan-2-ol (monoisopropanolamine, MIPA) with formaldehyde (in the molar ratio 1:1). The condensation product is a colourless to yellow liquid which is storage-stable and has a shelf life of more than 36 months.
The composition has good bactericidal action, a broad, balanced activity spectrum (including sulphate-reducing bacteria), good instantaneous action, good anticorrosive properties and is free of nitrate, nitrosating agents and organically bonded chlorine (thus does not contribute to the AOX value).
A disadvantage of the concentrate is the high viscosity of the product, in particular at low temperature. Although dilute TTT solutions can be prepared, namely i) from Grotan® WS by dilution with water, ii) by reaction of aqueous MIPA solution with paraformaldehyde or iii) by reaction of MIPA with formalin solution, the water-diluted solution and the preparation in diluted form unfortunately have the disadvantage that the solution assumes an intense red colour upon storage and, in contrast to the highly concentrated Grotan® WS, is not storage-stable. In general, the stability decreases with increasing dilution. A low-viscosity preparation with an advantageously high content of TTT and with improved stability is therefore sought.
DE 102 44 442 A1 discloses low-emission formaldehyde depot preparations with a content of a) at least one formal and b) at least one emission-reducing additive selected from urea, urea derivatives, amino acids, guanidine and guanidine derivatives, with certain specific active ingredients being excluded.
DE 10 2004 014 447 A1 describes N-formal-containing preservatives which also comprise emission-reducing additives selected from urea, urea derivatives, amino acids, guanidine and guanidine derivatives, and monoethylene glycol.
DE 10 2012 203 003 A1 describes liquid preparations for the reduction of free oxygen in industrial waters. The preparation comprises a) N-formal, b) dialkylhydroxylamine, and optionally c) antioxidant and d) alkalizing agent. The intended amount of alkalizing agent is high and is said to ensure that a sufficiently alkaline pH is maintained in the use dilution because this improves the action of the diethylhydroxylamine used as oxygen scavenger.
According to the teaching of EP 0 347 815 A2, alkanolamines are used for the stabilization of triazine derivatives. In this connection, the additional presence of surfactants is obligatorily prescribed. The surfactants used in the examples, however, are poorly biodegradable. It was therefore also an object of the present invention to provide preparations with a content of formaldehyde depot compound in which the use of surfactants is not obligatory.
Surprisingly, it has now been found that these objects are achieved by a preparation which comprises:
a)—10 to 80% by weight of α,α′,α″-trimethyl 1,3,5-triazine 1,3,5-(2H,4H,6H)triethanol (TTT) and
b)—One or more additives selected from                i.—Ammonia,        ii.—Alkanolamines with primary amino group and alkyl group having at most eight carbon atoms and        iii.—Alkylamines with primary amino group and alkyl group having at most eight carbon atoms,where the weight ratio a):b) is in the range from 100:30 to 100:1.        